1. Field of the Invention
The present invention relates to an organic light emitting display and fabrication method thereof, and more particularly, the present invention relates to an organic light emitting display and fabrication method thereof in which UV-rays are prevented from impinging upon organic light emitting diodes through a substrate during or after fabricating processes, bending or damage is prevented, and fabrication process time is shortened.
2. Description of the Related Art
In general, an organic light emitting display is a self-emissive display device that emits light when electrons and holes are joined by supplying a current to a fluorescent or phosphorescent organic compound. An image is displayed by voltage driving or current writing n×m organic light emitting diodes.
Such an organic light emitting display, as shown in FIG. 1, includes an anode (ITO: Indium Tin Oxide), an organic thin film and a cathode electrode (metal). The organic thin film is composed of an EMitting Layer (EML) that emits light by generating an exciton as the electrons and holes are joined, an Electron Transport Layer (ETL) that controls the moving speed of the electrons, and a Hole Transport Layer (HTL) that controls the moving speed of the holes. Furthermore, an Electron Injecting Layer (EIL) may be formed in the ETL, and a Hole Injecting Layer (HIL) may be formed in the HTL.
Such an organic light emitting display is well used as a moving picture display device because of it's advantages in terms of wide viewing angles, fast response times, self light emission, and low power consumption, and can be fabricated to be light and thin. Also, the organic light emitting display can be fabricated at a low temperature, and can be fabricated at a low cost because of simple fabricating processes. Furthermore, it is expected that the organic light emitting display will replace conventional flat display devices, since organic light emitting material technology and process technology have been increasingly developed.
An organic light emitting display is required for thicknesses of 1 mm or below, since electronic appliances, such as cellular telephones, Personal Digital Assistants (PDAs), notebook computers, computer monitors and television sets are increasingly being made in a thin and compact size. However, protective film technology capable of replacing encapsulation technology has not been developed well enough, and thus, it is difficult to fabricate an organic light emitting display having thickness of 1 mm or below.
Therefore, for fabricating the organic light emitting display having thickness of 1 mm or below, a method of fabricating a slim organic light emitting display by respectively forming diode layers (a semiconductor layer and organic light emitting diode, etc.) on two glass substrates, bonding the glass substrates so that the respective diode layers face each other, and removing a surface of the glass substrate without the diode layer by means of an etching or grinding process is described in Japanese Patent Nos. JP 2005-340182, JP 2005-222930 and JP 2005-222789.
However, there is a problem in this method in that the fabricating process time is prolonged, because the semiconductor layers or the organic light emitting diodes are respectively formed on the glass substrates, and then an etching or grinding process is executed. Furthermore, the production yield is low because the glass substrate, semiconductor layer and organic light emitting diode are often damaged or broken during the bonding process, and thus the fabrication cost is high.
Of course, the glass substrate having a thickness of 1 mm or below can be fabricated and then the diode layer formed on the surface of the glass substrate. However, there is a problem in that the thickness of the glass substrate is too thin, and thus, the glass substrate is bent or broken by mechanical contact with the fabricating machine during the fabrication process.